DSS 30" Premium Fiberglass Target Practice Arrows with Screw-In Tips (12 Pack) High quality fiberglass standard target practice arrows for recurve bow, compound bow, or long bow. Colored plastic fletching & nock.rounded permanent nickel-plated stainless steel bullet tip perfect for target practice beginners & hunting Nocked, fletched, tipped and ready to shoot Diameter: 8.0mm.For draw weight of 40-60 pounds bows The nocks can be adjusted. Pls fixed them by glue before your first shoot. Note: the nock's way is different with the bows(recurve bow, compound bow and long bow).